1. Field
The present invention relates to a backlight unit and a display device therewith.
2. Discussion of the Related Art
In general, a liquid crystal display device is used widely as a monitor of a cellular phone or a computer and a display device of a television set along with a plasma display panel, or an electro-luminescence display device owing to an excellent visibility compared to a cathode ray tube CRT, low average power consumption and low heat generation compared to the same screen sized CRT.
The liquid crystal display device is driven by utilizing optical anisotropy and polarization of liquid crystals. Since the liquid crystals are thin and lengthy, molecules of the liquid crystals can be oriented, enabling to control molecular orientation of the liquid crystals by applying an electric field to the liquid crystals, artificially.
Therefore, if the orientation of the liquid crystal molecules is controlled as desired, the orientation of the liquid crystal molecules changes, causing a light to refract in a direction of the orientation of the liquid crystal molecules by the optical anisotropy to display picture information.
However, since the liquid crystal display device is a light receiving device that can not emit the light spontaneously, to require a separate light source, the liquid crystal display device uses the backlight unit as a light source.
That is, the liquid crystal display device can display a picture by directing the light from the backlight unit to an overlying liquid crystal panel and controlling a quantity of the light transmitting through the liquid crystals by varying the orientation of the liquid crystals.